CBX3 is a component of heterochromatin‐associated proteins that binds specifically to trimethylated lysine 9 of histone H3 (H3K9me3), leading to the formation of heterochromatin.[20] CBX3 modulates numerous cellular processes, such as cell growth, cell differentiation, and DNA damage, by suppressing the expression of various genes.[20] CBX3 has recently been identified as a potential marker of carcinogenesis due to its high expression in several human cancer types, including colorectal cancer, lung cancer, hepatocellular carcinoma, and pancreatic cancer. Here, CBX3 is linked to lung cancer.